<?php

declare(strict_types=1);

/*
 * This file is a part of the DiscordPHP project.
 *
 * Copyright (c) 2015-present David Cole <david.cole1340@gmail.com>
 *
 * This file is subject to the MIT license that is bundled
 * with this source code in the LICENSE.md file.
 */

namespace Discord\Parts\Embed;

use Carbon\Carbon;
use Discord\Helpers\Collection;
use Discord\Helpers\ExCollectionInterface;
use Discord\Parts\Channel\Attachment;
use Discord\Parts\Part;

use function Discord\poly_strlen;

/**
 * An embed object to be sent with a message.
 *
 * @link https://discord.com/developers/docs/resources/message#embed-object-embed-structure
 *
 * @since 4.0.3
 * @since 10.19.0 The `provider` property was added and `thumbnail` was updated to return `Thumbnail`.
 *
 * @property      ?string|null                          $title       The title of the embed.
 * @property-read ?string|null                          $type        The type of the embed (always "rich" for webhook embeds).
 * @property      ?string|null                          $description A description of the embed.
 * @property      ?string|null                          $url         The URL of the embed.
 * @property      ?Carbon|null                          $timestamp   A timestamp of the embed.
 * @property      ?int|null                             $color       The color of the embed.
 * @property      ?Footer|null                          $footer      The footer of the embed.
 * @property      ?Image|null                           $image       The image of the embed.
 * @property      ?Thumbnail|null                       $thumbnail   The thumbnail of the embed.
 * @property-read ?Video|null                           $video       The video of the embed.
 * @property-read ?Provider|null                        $provider    The provider of the embed.
 * @property      ?Author|null                          $author      The author of the embed.
 * @property      ?ExCollectionInterface<Field>|Field[] $fields      A collection of embed fields (max of 25).
 */
class Embed extends Part
{
    public const TYPES = [
        0 => Embed::class, // Fallback for unknown types
        self::TYPE_RICH => EmbedRich::class,
        self::TYPE_IMAGE => EmbedImage::class,
        self::TYPE_VIDEO => EmbedVideo::class,
        self::TYPE_GIFV => EmbedGifv::class,
        self::TYPE_ARTICLE => EmbedArticle::class,
        self::TYPE_LINK => EmbedLink::class,
        self::TYPE_POLL_RESULT => EmbedPollResult::class,
    ];

    /** Generic embed rendered from embed attributes. */
    public const TYPE_RICH = 'rich';
    /** Image embed. */
    public const TYPE_IMAGE = 'image';
    /** Video embed. */
    public const TYPE_VIDEO = 'video';
    /** Animated gif image embed rendered as a video embed. */
    public const TYPE_GIFV = 'gifv';
    /** Article embed. */
    public const TYPE_ARTICLE = 'article';
    /** Link embed. */
    public const TYPE_LINK = 'link';
    /** Poll result embed. */
    public const TYPE_POLL_RESULT = 'poll_result';

    /**
     * @inheritDoc
     */
    protected $fillable = [
        'title',
        'type',
        'description',
        'url',
        'timestamp',
        'color',
        'footer',
        'image',
        'thumbnail',
        'video',
        'provider',
        'author',
        'fields',
    ];

    /**
     * Gets the timestamp attribute.
     *
     * @return Carbon|null The timestamp attribute.
     *
     * @throws \Exception
     */
    protected function getTimestampAttribute(): ?Carbon
    {
        return $this->attributeCarbonHelper('timestamp');
    }

    /**
     * Gets the footer attribute.
     *
     * @return Footer|null The footer attribute.
     */
    protected function getFooterAttribute(): ?Footer
    {
        return $this->attributePartHelper('footer', Footer::class);
    }

    /**
     * Gets the image attribute.
     *
     * @return Image|null The image attribute.
     */
    protected function getImageAttribute(): ?Image
    {
        return $this->attributePartHelper('image', Image::class);
    }

    /**
     * Gets the thumbnail attribute.
     *
     * @return Thumbnail|null The thumbnail attribute.
     */
    protected function getThumbnailAttribute(): ?Thumbnail
    {
        return $this->attributePartHelper('thumbnail', Thumbnail::class);
    }

    /**
     * Gets the video attribute.
     *
     * @return Video|null The video attribute.
     */
    protected function getVideoAttribute(): ?Video
    {
        return $this->attributePartHelper('video', Video::class);
    }

    /**
     * Gets the provider attribute.
     *
     * @return Provider|null The provider attribute.
     */
    protected function getProviderAttribute(): ?Provider
    {
        return $this->attributePartHelper('provider', Provider::class);
    }

    /**
     * Gets the author attribute.
     *
     * @return Author|null The author attribute.
     */
    protected function getAuthorAttribute(): ?Author
    {
        return $this->attributePartHelper('author', Author::class);
    }

    /**
     * Gets the fields attribute.
     *
     * @return ExCollectionInterface<Field>|Field[]
     */
    protected function getFieldsAttribute(): ExCollectionInterface
    {
        return $this->attributeCollectionHelper('fields', Field::class, 'name');
    }

    /**
     * Sets the fields attribute.
     *
     * @param Field[] ...$fields
     */
    protected function setFieldsAttribute($fields): void
    {
        $this->attributes['fields'] = [];
        $this->addField(...$fields);
    }

    /**
     * Sets the color of this embed.
     *
     * @param mixed $color
     *
     * @throws \InvalidArgumentException
     */
    protected function setColorAttribute($color): void
    {
        $this->attributes['color'] = $this->resolveColor($color);
    }

    /**
     * Sets the description of this embed.
     *
     * @param string $description Maximum length is 4096 characters.
     *
     * @throws \LengthException Embed text too long.
     */
    protected function setDescriptionAttribute($description): void
    {
        if (poly_strlen($description) === 0) {
            $this->attributes['description'] = null;
        } elseif (poly_strlen($description) > 4096) {
            throw new \LengthException('Embed description can not be longer than 4096 characters');
        } else {
            if ($this->exceedsOverallLimit(poly_strlen($description))) {
                throw new \LengthException('Embed text values collectively can not exceed than 6000 characters');
            }

            $this->attributes['description'] = $description;
        }
    }

    /**
     * Sets the type of the embed.
     *
     * @deprecated 10.0.0 Type `rich` will always be used in API.
     *
     * @param string $type
     *
     * @throws \InvalidArgumentException Invalid embed type.
     */
    protected function setTypeAttribute($type): void
    {
        if (! in_array($type, $this->getEmbedTypes())) {
            throw new \InvalidArgumentException('Given type "'.$type.'" is not a valid embed type.');
        }

        $this->attributes['type'] = $type;
    }

    /**
     * Set the title of this embed.
     *
     * @param string $title Maximum length is 256 characters.
     *
     * @throws \LengthException Embed text too long.
     *
     * @return $this
     */
    protected function setTitleAttribute(string $title): self
    {
        if (poly_strlen($title) === 0) {
            $this->attributes['title'] = null;
        } elseif (poly_strlen($title) > 256) {
            throw new \LengthException('Embed title can not be longer than 256 characters');
        } elseif ($this->exceedsOverallLimit(poly_strlen($title))) {
            throw new \LengthException('Embed text values collectively can not exceed than 6000 characters');
        } else {
            $this->attributes['title'] = $title;
        }

        return $this;
    }

    /**
     * Sets the title of the embed.
     *
     * @param string $title
     *
     * @return $this
     */
    public function setTitle(string $title): self
    {
        $this->title = $title;

        return $this;
    }

    /**
     * Sets the type of the embed.
     *
     * @deprecated 10.0.0 Type `rich` will always be used in API.
     *
     * @param string $type
     *
     * @return $this
     */
    public function setType(string $type): self
    {
        $this->type = $type;

        return $this;
    }

    /**
     * Sets the description of the embed.
     *
     * @param string $description
     *
     * @return $this
     */
    public function setDescription(string $description): self
    {
        $this->description = $description;

        return $this;
    }

    /**
     * Sets the color of the embed.
     *
     * @param mixed $color
     *
     * @return $this
     */
    public function setColor($color): self
    {
        $this->color = $color;

        return $this;
    }

    /**
     * Adds a field to the embed.
     *
     * @param Field|array $fields
     *
     * @throws \OverflowException Embed exceeds 25 fields.
     *
     * @return $this
     */
    public function addField(...$fields): self
    {
        foreach ($fields as $field) {
            if (count($this->fields) > 25) {
                throw new \OverflowException('Embeds can not have more than 25 fields.');
            }

            if ($field instanceof Field) {
                $field = $field->getRawAttributes();
            }

            $this->attributes['fields'][] = $field;
        }

        return $this;
    }

    /**
     * Adds a field to the embed with values.
     *
     * @param string $name   Maximum length is 256 characters.
     * @param string $value  Maximum length is 1024 characters.
     * @param bool   $inline Whether this field gets shown with other inline fields on one line.
     *
     * @throws \OverflowException
     *
     * @return $this
     */
    public function addFieldValues(string $name, string $value, bool $inline = false): static
    {
        return $this->addField([
            'name' => $name,
            'value' => $value,
            'inline' => $inline,
        ]);
    }

    /**
     * Set the author of this embed.
     *
     * @param string                 $name    Maximum length is 256 characters.
     * @param string|Attachment|null $iconurl The URL to the icon, only http(s) and attachments URLs are allowed.
     * @param string|null            $url     The URL to the author, only http(s) URLs are allowed.
     *
     * @throws \LengthException          Embed text too long.
     * @throws \InvalidArgumentException Invalid scheme provided.
     *
     * @return $this
     */
    public function setAuthor(string $name, $iconurl = null, ?string $url = null): self
    {
        $length = poly_strlen($name);
        if ($length === 0) {
            $this->author = null;
        } elseif ($length > 256) {
            throw new \LengthException('Author name can not be longer than 256 characters.');
        } elseif ($this->exceedsOverallLimit($length)) {
            throw new \LengthException('Embed text values collectively can not exceed than 6000 characters');
        }

        if ($iconurl instanceof Attachment) {
            $iconurl = 'attachment://'.$iconurl->filename;
        }

        $this->ensureValidUrl($iconurl);

        $this->ensureValidUrl($url, ['http', 'https']);

        $this->author = [
            'name' => $name,
            'icon_url' => $iconurl,
            'url' => $url,
        ];

        return $this;
    }

    /**
     * Set the footer of this embed.
     *
     * @param string                 $text    Maximum length is 2048 characters.
     * @param string|Attachment|null $iconurl The URL to the icon, only http(s) and attachments URLs are allowed.
     *
     * @throws \LengthException          Embed text too long.
     * @throws \InvalidArgumentException Invalid scheme provided.
     *
     * @return $this
     */
    public function setFooter(string $text, $iconurl = null): self
    {
        $length = poly_strlen($text);
        if ($length === 0) {
            $this->footer = null;
        } elseif ($length > 2048) {
            throw new \LengthException('Footer text can not be longer than 2048 characters.');
        } elseif ($this->exceedsOverallLimit($length)) {
            throw new \LengthException('Embed text values collectively can not exceed than 6000 characters');
        }

        if ($iconurl instanceof Attachment) {
            $iconurl = 'attachment://'.$iconurl->filename;
        }

        $this->ensureValidUrl($iconurl);

        $this->footer = [
            'text' => $text,
            'icon_url' => $iconurl,
        ];

        return $this;
    }

    /**
     * Set the image of this embed.
     *
     * @param string|Attachment|null $url The URL to the image, only http(s) and attachments URLs are allowed.
     *
     * @throws \InvalidArgumentException Invalid scheme provided.
     *
     * @return $this
     */
    public function setImage($url): self
    {
        if ($url instanceof Attachment) {
            $url = 'attachment://'.$url->filename;
        }

        $this->ensureValidUrl($url);

        $this->image = ['url' => $url];

        return $this;
    }

    /**
     * Set the thumbnail of this embed.
     *
     * @param string|Attachment|null $url The URL to the thumbnail, only http(s) and attachments URLs are allowed.
     *
     * @throws \InvalidArgumentException Invalid scheme provided.
     *
     * @return $this
     */
    public function setThumbnail($url): self
    {
        if ($url instanceof Attachment) {
            $url = 'attachment://'.$url->filename;
        }

        $this->ensureValidUrl($url);

        $this->thumbnail = ['url' => $url];

        return $this;
    }

    /**
     * Set the timestamp of this embed.
     *
     * @param int|null $timestamp
     *
     * @throws \Exception
     *
     * @return $this
     */
    public function setTimestamp(?int $timestamp = null): self
    {
        $this->timestamp = Carbon::parse($timestamp)->format('c');

        return $this;
    }

    /**
     * Set the URL of this embed.
     *
     * @param string $url
     *
     * @return $this
     */
    public function setURL(string $url): self
    {
        $this->url = $url;

        return $this;
    }

    /**
     * Ensures a URL is valid for use in embeds.
     *
     * @param ?string $url
     * @param array   $allowed Allowed URL scheme
     *
     * @throws \DomainException
     */
    protected function ensureValidUrl(?string $url = null, array $allowed = ['http', 'https', 'attachment']): void
    {
        if (null !== $url && ! in_array(parse_url($url, PHP_URL_SCHEME), $allowed)) {
            throw new \DomainException('URL scheme only supports '.implode(', ', $allowed));
        }
    }

    /**
     * Checks to see if adding a property has put us over Discord's 6000
     * characters overall limit.
     *
     * @param int $addition
     *
     * @return bool
     */
    protected function exceedsOverallLimit(int $addition): bool
    {
        $total = (
            poly_strlen(($this->title ?? '')) +
            poly_strlen(($this->description ?? '')) +
            poly_strlen(($this->footer['text'] ?? '')) +
            poly_strlen(($this->author['name'] ?? '')) +
            $addition
        );

        foreach ($this->fields as $field) {
            $total += poly_strlen($field['name']);
            $total += poly_strlen($field['value']);
        }

        return ($total > 6000);
    }

    /**
     * Resolves a color to an integer.
     *
     * @param array|int|string $color
     *
     * @throws \InvalidArgumentException `$color` cannot be resolved
     *
     * @return int
     */
    protected static function resolveColor($color): int
    {
        if (is_numeric($color)) {
            $color = (int) $color;
        }

        if (is_int($color)) {
            return $color;
        }

        if (! is_array($color)) {
            return hexdec((str_replace('#', '', (string) $color)));
        }

        if (count($color) < 1) {
            throw new \InvalidArgumentException('Color "'.var_export($color, true).'" is not resolvable');
        }

        return (($color[0] << 16) + (($color[1] ?? 0) << 8) + ($color[2] ?? 0));
    }

    /**
     * Returns all possible embed types.
     *
     * @return array
     */
    private static function getEmbedTypes(): array
    {
        return [
            self::TYPE_RICH,
            self::TYPE_IMAGE,
            self::TYPE_VIDEO,
            self::TYPE_GIFV,
            self::TYPE_ARTICLE,
            self::TYPE_LINK,
            self::TYPE_POLL_RESULT,
        ];
    }
}
